Radiotherapy is an important part of the standard treatment regimen for rectal cancer, bringing survival benefits and improved quality of life to patients with rectal cancer. However, the radiotherapy resistance of rectal cancer patients greatly limits the effectiveness of treatment and affects the prognosis of patients. The emergence of nanoparticles provides a new way to improve radiotherapy resistance of rectal cancer, which can overcome radiotherapy resistance by inhibiting DNA damage repair, affecting cell cycle, targeting delivery, enhancing DNA damage, and regulating tumor microenvironment, etc. In this article, complex coordination mechanism leading to radiotherapy resistance in rectal cancer was reviewed, current relevant studies on nanoparticles in improving radiotherapy response in rectal cancer were summarized, and the feasibility and future research direction of the combination of nanoparticles and radiotherapy in clinical treatment of rectal cancer were discussed.

Radiotherapy is an important part of the standard treatment regimen for rectal cancer, bringing survival benefits and improved quality of life to patients with rectal cancer. However, the radiotherapy resistance of rectal cancer patients greatly limits the effectiveness of treatment and affects the prognosis of patients. The emergence of nanoparticles provides a new way to improve radiotherapy resistance of rectal cancer, which can overcome radiotherapy resistance by inhibiting DNA damage repair, affecting cell cycle, targeting delivery, enhancing DNA damage, and regulating tumor microenvironment, etc. In this article, complex coordination mechanism leading to radiotherapy resistance in rectal cancer was reviewed, current relevant studies on nanoparticles in improving radiotherapy response in rectal cancer were summarized, and the feasibility and future research direction of the combination of nanoparticles and radiotherapy in clinical treatment of rectal cancer were discussed.